I have updated my Gentoo installation for the first time after several months, and now I cannot read my encrypted Raid array any more.

When I am trying to access the Raid array with

Code:

cryptsetup luksOpen /dev/md1 raid

I am getting the following error message:

Code:

Cannot initialize device-mapper. Is dm_mod kernel module loaded?

I have tried to downgrade the version of cryptsetup, compiled a new kernel version, downgraded the version of udev, downgraded the version of lvm2,
but nothing was resolving the error. I am getting a little desperate now....

Let me try to provide some more background information:

1) The kernel configuration has not changed, and it was working previously with the kernel that is used.
In particular, device mapper is compiled into the kernel and available.
In /proc/misc, there is an entry "236 device-mapper".

2) The node /dev/md1 is visible.

3) The problem is with the device mapper itself.
Commands such as

Code:

cryptsetup luksDump -v /dev/md1

are successful.

4) dmraid is not installed. Maybe this has been uninstalled with the update?
However, after an emerge of dmraid, the problem persists.

Do you have any idea what I could do?
Maybe I could compile a new kernel with a device mapper module dm_mod and load that module.
But I am a little hesitant to do so because I think that this is not the problem, the
device mapper compiled into the kernel was working previously.

Last edited by Rainer06 on Mon Apr 29, 2013 5:07 am; edited 3 times in total

Newer cryptsetup has wider encryption keys by default. Current~unstable cryptsetup needs a hint to decrypt with older kind of key. Lazily I stabled this ebuild with package.accept_keywords._________________fun2gen2

There should be a big warning about this for everybody updating libgcrypt.
I just checked the emerge logs, but there is no info about this.
Please add this information for the benefit of everybody else
using encryption.